Patent FR-2977504-A1 (FR)
Title: Drive system, useful for e.g. moving a suction device at a bottom of a sedimentation tank for receiving liquid containing suspended solids to be removed, comprises a cable, a pulling device, a marking device, and a sensor
Inventor: ROBIN YANNICK
IPC: B01D21/24
Filed: 2011-07-05
Abstract: The drive system comprises a cable adapted to be connected to a suction device, a device (16) for pulling the suction device through the cable for moving the suction device to suck suspended solids that are deposited on a bottom of a sedimentation tank, a marking device attached to the cable, and a sensor adapted to detect a passage of the marking device proximate to the sensor indicating a stroke end of the suction device to the bottom of the sedimentation tank. The pulling device comprises a drum having a first winding portion (34) and a second winding portion (35), and a motor (31). The drive system comprises a cable adapted to be connected to a suction device, a device (16) for pulling the suction device through the cable for moving the suction device to suck suspended solids that are deposited on a bottom of a sedimentation tank, a marking device attached to the cable, and a sensor adapted to detect a passage of the marking device proximate to the sensor indicating a stroke end of the suction device to the bottom of the sedimentation tank. The pulling device comprises a drum having a first winding portion (34) and a second winding portion (35), a motor (31), a gear (32), and a security unit to disconnect the motor of the drum when a drive torque exerted on the drum exceeds a predetermined threshold. The drum is adapted to be rotationally driven in a first rotational direction and a second rotational direction to wind the cable on the first and second winding portions, which cause the movement of the suction device in a first movement direction and a second movement direction. The second rotational direction is opposite to the first rotational direction. The second movement direction is opposite to the first movement direction. The motor is adapted to drive the drum in rotation by the gear. The security unit comprises a breakable component adapted to break when the drive torque exceeds the predetermined threshold. The marking device is translationally driven by the drum. The sensor is further adapted to detect the passage of the marking device proximate to the sensor indicating rotation of the drum beyond a limiting winding position. The system further comprises: an endless screw rotatably connected to the drum; a frame (30) adapted to be arranged on an edge of the sedimentation tank to withstand the pulling device; a guide roller for passing the cable from the pulling device, along a vertical wall of the sedimentation tank, to the suction device; and a tensioning member. A rotation of the endless screw causes the translation of the marking element. The frame comprises a base for fixing the frame on a slab. The base includes a unit for adjusting the height of the base for adjusting a voltage of the cable. The guide roller is fixed to a fixed structure, and receives the cable. The tensioning member is placed between the fixed structure and the guide roller, and is adapted for tensioning the cable during assembly of the drive system. An independent claim is included for an installation for treating liquid containing suspended solids to be removed.